The South African context is one of high risk for adolescent substance use and delinquency. The post-Apartheid environment consists of major political, economic, and social changes, discrimination and increasing violence. It is important to understand how adolescent substance use and delinquency develop independently as well as how these behaviors co-occur in this context. The current study will uniquely contribute to research on substance use and delinquent behaviors among South African adolescents, and in particular, on their methamphetamine use. The research study aims to identify latent classes (subgroups) of co-occurring adolescent substance users and delinquents and to examine how these subgroups change over time. Results of the current study have two major implications for prevention research and public health. First, better understanding of how adolescent substance use and delinquency occur in South Africa may inform the theory underlying the design of prevention programs in high risk contexts in other parts of South Africa. Second, using a person-oriented approach toward the study of adolescent substance use and delinquency may provide unique insight into possible subgroups of adolescents, affecting whether programs choose to target specific risk behaviors versus multiple risk behaviors. PUBLIC HEALTH RELEVANCE: The application of innovative statistical methods may be one way to better understand co-occurring adolescent substance use and delinquency.